Firewall “cut-out”

[pinza]

Hi,
My 3.8 FHC is undergoing a full restoration. Before my ownership the car sustained damage to the firewall where the rear engine mount attaches, as per photo (not my car).
We have welded it up but need to make the cutout where I have circled in yellow. If someone could supply dimensions A (to the front of car), B (on the firewall) and C, I would be most grateful.
I tried to do this on a car with the engine in place, but found it too difficult. So I am hoping someone has an accessible firewall.
Thanks in advance,
Glenn

[christopher storey]

I cannot give you dimensions , but if you draw a vertical line down from the lowest point of the inside near vertical flange, that will give you the narrowest part of the cutout ( B in your drawing ) . If you then go forwards about one-third of the total fore/aft measurement of the horizontal flange ( C in your drawing ) , and draw a line across the flange from the narrowest part that will give you the portion of the horizontal flange which you need to leave in place ( Not shown in your drawing, but roughly 1/3 of C ) . From the narrowest point, then "chamfer" the cutout outwards at about 30 degrees to the fore/aft line, and you will then have the shape you need

NB this is NOT an engine mounting ; it is a stay bar only, and the apparatus should bear no part of the engine's weight . The setup procedure is given in the workshop manual

[mxke]

Hi Glenn
Hopefully this helps. From a late 62 OTS under restoration.
Mike

[pinza]

Thank you both Christopher and Mike.
We will use your information to keep the project moving - just what we needed.
And thank you, Christopher, for the tip about it not being a “mount”. We will take your advice and refer to the manual and fit it correctly.
Australia is a great place to restore a Jag! I can post a problem at night knowing full well that our friends in the UK and Europe (formerly EU ??) and North America will work diligently while I sleep and supply me with an answer when I wake up - no time wasted. It does make up a little bit for having to wait for parts to arrive !
Thanks again.
Glenn

[rfs1957]

We think it's great but the other way round.

On a couple of occasions I've gone to bed wracking my brain over a conundrum, having posted the query here beforehand, only to wake up and find a Down-Under solution has been posted overnight.

I have a clever piece of software that publishes Australian messages the correct way up, it's easier on the arms.

[Gfhug]

I have a clever piece of software that publishes Australian messages the correct way up, it's easier on the arms.